Project Summary/Abstract The overall goal of this research program is to understand how parallel retinofugal pathways are established during development. This proposal focuses on the question of how retinal ganglion cell (RGC) axons select their correct targets and target layers in the brain during development. RGC axon-target and axon-layer matching are both critical aspects of visual circuit organization and yet, very little is known about how they develop in mammals. We propose to study the development of these connections in transgenic mice where specific RGC subtypes express fluorescent proteins and in which specific genes are absent or misexpressed in the retinofugal pathway. The specific aims of this proposal are to 1) characterize the cellular events that enable RGCs carrying different qualities of visual information to recognize their appropriate targets in the brain, 2) test the hypothesis that the adhesion molecule cadherin-6 controls RGC axon-target matching 3) test the hypothesis that lamina specific targeting of axons from direction selective RGCs to the superior colliculus is mediated by the adhesion molecule cadherin-7. Results from these experiments should lead to new understanding of how mammalian visual circuits are established and inform strategies for maintaining and replenishing visual circuits in response to injury or disease.